hitunglah masa mr dari senyawa berikut.

a. Na2SO4:
2 Na >> 23.2 = 46
1 S >> 32.1 = 32
4 O >> 16.4 = 64

Mr = 142.

b. (NH4)3PO4:
3 N >> 14.3 = 42
12 H >> 1.12 = 12
1 P >> 31.1 = 31
4 O >> 16.4 = 64

Mr = 149.

c. NaNO3 . 4H2O
1 Na >> 23.1 = 23
1 N >> 14.1 = 14
8 H >> 1.8 = 8
7 O >> 16.7 = 112

Mr = 157.